Search

Through dedicated batch tests using the enriched sludge dominated by sulfur-oxidizing bacteria (SOB), the potential transformation of hydroxylamine (NH 2 OH) by SOB and the effects of NH 2 OH on the rate-limiting sequential reduction processes of sulfur-driven autotrophic denitrification (SDAD) were systematically explored in this study. The results indicated that NH 2 OH might be first converted to NO by SOB and then participate in the SDAD process, thus accelerating the utilization of S 2- and contributing to the formation of N 2 O. Up to 3.5 mg-N/L NH 2 OH didn't affect the NO 3 - or NO 2 - reduction of SDAD, during which no significant changes were observed for the NH 2 OH concentration. Comparatively, even though NH 2 OH had no direct impact on the N 2 O reduction of SDAD, it could be consumed and therefore affect the depletion of N 2 O indirectly by regulating the toxic effect and electron supply of S 2- . These findings provide novel implications for applying NH 2 OH to SDAD-based integrated processes for biological nitrogen removal., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)